refactor avatar display: unify rendering and resolve at use time

- Extract buildAvatarWidget() in common.dart to share avatar rendering
    logic across desktop settings, desktop CM and mobile CM
  - Add resolve_avatar_url() in Rust, exposed via FFI (SyncReturn),
    to resolve relative avatar paths (e.g. "/avatar/xxx") to absolute URLs
  - Store avatar as-is in local config, only resolve when displaying
    (settings page) or sending (LoginRequest)
  - Resolve avatar in LoginRequest before sending to remote peer
  - Add error handling for network image load failures
  - Guard against empty client.name[0] crash
  - Show avatar in mobile settings page account tile

Signed-off-by: 21pages <sunboeasy@gmail.com>

flutter/lib/common.dart

@@ -4118,3 +4118,43 @@ String mouseButtonsToPeer(int buttons) {
       return '';
   }
 }
+
+/// Build an avatar widget from an avatar URL or data URI string.
+/// Returns [fallback] if avatar is empty or cannot be decoded.
+/// [borderRadius] defaults to [size]/2 (circle).
+Widget? buildAvatarWidget({
+  required String avatar,
+  required double size,
+  double? borderRadius,
+  Widget? fallback,
+}) {
+  final trimmed = avatar.trim();
+  if (trimmed.isEmpty) return fallback;
+
+  ImageProvider? imageProvider;
+  if (trimmed.startsWith('data:image/')) {
+    final comma = trimmed.indexOf(',');
+    if (comma > 0) {
+      try {
+        imageProvider = MemoryImage(base64Decode(trimmed.substring(comma + 1)));
+      } catch (_) {}
+    }
+  } else if (trimmed.startsWith('http://') || trimmed.startsWith('https://')) {
+    imageProvider = NetworkImage(trimmed);
+  }
+
+  if (imageProvider == null) return fallback;
+
+  final radius = borderRadius ?? size / 2;
+  return ClipRRect(
+    borderRadius: BorderRadius.circular(radius),
+    child: Image(
+      image: imageProvider,
+      width: size,
+      height: size,
+      fit: BoxFit.cover,
+      errorBuilder: (_, __, ___) =>
+          fallback ?? SizedBox.shrink(),
+    ),
+  );
+}

flutter/lib/desktop/pages/desktop_setting_page.dart

@@ -2061,7 +2061,8 @@ class _AccountState extends State<_Account> {
                             overflow: TextOverflow.ellipsis,
                             style: TextStyle(
                               fontSize: 13,
-                              color: Theme.of(context).textTheme.bodySmall?.color,
+                              color:
+                                  Theme.of(context).textTheme.bodySmall?.color,
                             ),
                           ),
                         ),
@@ -2076,28 +2077,13 @@ class _AccountState extends State<_Account> {
   }
 
   Widget? _buildUserAvatar() {
-    final avatar = gFFI.userModel.avatar.value.trim();
-    if (avatar.isEmpty) return null;
-    const radius = 22.0;
-    if (avatar.startsWith('data:image/')) {
-      final comma = avatar.indexOf(',');
-      if (comma > 0) {
-        try {
-          return CircleAvatar(
-            radius: radius,
-            backgroundImage: MemoryImage(base64Decode(avatar.substring(comma + 1))),
-          );
-        } catch (_) {
-          return null;
-        }
-      }
-    } else if (avatar.startsWith('http://') || avatar.startsWith('https://')) {
-      return CircleAvatar(
-        radius: radius,
-        backgroundImage: NetworkImage(avatar),
-      );
-    }
-    return null;
+    // Resolve relative avatar path at display time
+    final avatar =
+        bind.mainResolveAvatarUrl(avatar: gFFI.userModel.avatar.value);
+    return buildAvatarWidget(
+      avatar: avatar,
+      size: 44,
+    );
   }
 }
 

flutter/lib/desktop/pages/server_page.dart

@@ -1,7 +1,6 @@
 // original cm window in Sciter version.
 
 import 'dart:async';
-import 'dart:convert';
 import 'dart:math';
 
 import 'package:flutter/material.dart';
@@ -569,37 +568,12 @@ class _CmHeaderState extends State<_CmHeader>
   bool get wantKeepAlive => true;
 
   Widget _buildClientAvatar() {
-    const borderRadius = BorderRadius.all(Radius.circular(15.0));
-    final avatar = client.avatar.trim();
-    if (avatar.startsWith('data:image/')) {
-      final comma = avatar.indexOf(',');
-      if (comma > 0) {
-        try {
-          final bytes = base64Decode(avatar.substring(comma + 1));
-          return ClipRRect(
-            borderRadius: borderRadius,
-            child: Image.memory(
-              bytes,
-              width: 70,
-              height: 70,
-              fit: BoxFit.cover,
-            ),
-          );
-        } catch (_) {}
-      }
-    } else if (avatar.startsWith('http://') || avatar.startsWith('https://')) {
-      return ClipRRect(
-        borderRadius: borderRadius,
-        child: Image.network(
-          avatar,
-          width: 70,
-          height: 70,
-          fit: BoxFit.cover,
-          errorBuilder: (_, __, ___) => _buildInitialAvatar(),
-        ),
-      );
-    }
-    return _buildInitialAvatar();
+    return buildAvatarWidget(
+      avatar: client.avatar,
+      size: 70,
+      borderRadius: 15,
+      fallback: _buildInitialAvatar(),
+    )!;
   }
 
   Widget _buildInitialAvatar() {
@@ -612,7 +586,7 @@ class _CmHeaderState extends State<_CmHeader>
         borderRadius: BorderRadius.circular(15.0),
       ),
       child: Text(
-        client.name[0],
+        client.name.isNotEmpty ? client.name[0] : '?',
         style: TextStyle(
           fontWeight: FontWeight.bold,
           color: Colors.white,

flutter/lib/mobile/pages/server_page.dart

@@ -1,5 +1,4 @@
 import 'dart:async';
-import 'dart:convert';
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -857,28 +856,17 @@ class ClientInfo extends StatelessWidget {
   }
 
   Widget _buildAvatar(BuildContext context) {
-    final avatar = client.avatar.trim();
-    if (avatar.isNotEmpty) {
-      if (avatar.startsWith('data:image/')) {
-        final comma = avatar.indexOf(',');
-        if (comma > 0) {
-          try {
-            return CircleAvatar(
-              backgroundImage: MemoryImage(base64Decode(avatar.substring(comma + 1))),
-            );
-          } catch (_) {}
-        }
-      } else if (avatar.startsWith('http://') || avatar.startsWith('https://')) {
-        return CircleAvatar(backgroundImage: NetworkImage(avatar));
-      }
-    }
-    // Show character as before if no avatar
-    return CircleAvatar(
+    final fallback = CircleAvatar(
       backgroundColor: str2color(
           client.name,
           Theme.of(context).brightness == Brightness.light ? 255 : 150),
-      child: Text(client.name[0]),
+      child: Text(client.name.isNotEmpty ? client.name[0] : '?'),
     );
+    return buildAvatarWidget(
+      avatar: client.avatar,
+      size: 40,
+      fallback: fallback,
+    )!;
   }
 }
 

flutter/lib/mobile/pages/settings_page.dart

@@ -689,7 +689,15 @@ class _SettingsState extends State<SettingsPage> with WidgetsBindingObserver {
                 title: Obx(() => Text(gFFI.userModel.userName.value.isEmpty
                     ? translate('Login')
                     : '${translate('Logout')} (${gFFI.userModel.accountLabelWithHandle})')),
-                leading: Icon(Icons.person),
+                leading: Obx(() {
+                  final avatar = bind.mainResolveAvatarUrl(
+                      avatar: gFFI.userModel.avatar.value);
+                  return buildAvatarWidget(
+                        avatar: avatar,
+                        size: 40,
+                      ) ??
+                      Icon(Icons.person);
+                }),
                 onPressed: (context) {
                   if (gFFI.userModel.userName.value.isEmpty) {
                     loginDialog();

flutter/lib/models/user_model.dart

@@ -34,6 +34,7 @@ class UserModel {
     }
     return '$preferred (@$username)';
   }
+
   WeakReference<FFI> parent;
 
   UserModel(this.parent) {
@@ -88,7 +89,6 @@ class UserModel {
       }
 
       final user = UserPayload.fromJson(data);
-      user.avatar = _resolveAvatar(user.avatar, url);
       _parseAndUpdateUser(user);
     } catch (e) {
       debugPrint('Failed to refreshCurrentUser: $e');
@@ -138,7 +138,6 @@ class UserModel {
     avatar.value = user.avatar;
     isAdmin.value = user.isAdmin;
     bind.mainSetLocalOption(key: 'user_info', value: jsonEncode(user));
-    _updateLocalUserInfo();
     if (isWeb) {
       // ugly here, tmp solution
       bind.mainSetLocalOption(key: 'verifier', value: user.verifier ?? '');